Arabinofuranosidases are capable of hydrolyzing terminal non-reducing alpha-L-arabinofuranoside residues in alpha-L-arabinosides and are classified as EC 3.2.1.55. Arabinofuranosidases have been isolated from several organisms including filamentous fungi. However, very few alpha-arabinofuranosidases able to liberate arabinose from di-substituted xyloses are known. From Bifidobacterium adolescentis an intracellular enzyme able to release arabinose from C3 of di-substituted xylose (also internally) has been described (Van Laere, 1997, Appl. Microbiol. Biotechnol, 47, 231-235 and Van den Broek, 2005, Applied Microbiology and Biotechnology). From barley an enzyme active on mono- and terminally di-substituted xyloses has been isolated, but it has little activity on internally di-substituted xyloses (Ferre, 2000, Eur. J. Biochem., 267, 6633-6641). An enzyme from Trichoderma reesei is possibly active on terminally di-substituted residues (activity seen on 3,5-di-O-alpha-Larabinofuranosyl-alpha-L-arabinofuranoside), but has no activity towards an oligo-substrate with internally C3 substituted arabinose (Nogawa, 1999, Appl. Environ. Microbiol., 65, 3964-3968).
A comparison with full-length prior-art sequences shows that the mature amino acid sequence shown in SEQ ID NO:2 has 72% homology with an amino acid sequence from Chaetomium globosum, and the corresponding DNA sequence in SEQ ID NO:1 shows 73% homology with that of the corresponding Chaetomium globosum DNA sequence. The homology between the sequence shown in SEQ ID NO:2 and the bacterial GH43 alpha-L-arabinofuranosidase from Bifidobacterium sp. is 25%. The mature amino acid sequence shown in SEQ ID NO:4 has 38% homology with the arabinofuranosidase from Aspergillus niger. 